Propeller blade



Jan. 8, 1952 G. L. DAKIN 2,582,107

PROPELLER BLADE Filed June 25, 1949 IN V EN TOR.

ATTORNE 5 Patented Jan. 8, 1952 UNITED STATES PATENT OFFICE 2,582,107 "momma ems]:

Guy L. Dakin, nmisviiiemeii. Application June 25, 1949', Serial at. 101,399

' mam-.- (01176- 159? This invention relates to air or water craft, and is particularly concerned with propellers, and is more particularly concerned with a construction of airplane propeller whereby greater efficiency is obtained.

In the past propellers have been made in conventional manner, that is, the blades being extended directly in opposite directions from each other, and from the hub. I have concentrated my efforts in the construction. of a propeller in which the blades partially extend in usual direction from the hub, and thereafter are curved in mariner which is a departure toa very large extent from the conventional construction of propellers.

It is therefore an object of the present invention to provide a propeller of increased eiflciency. It is a further object to provide a propeller in which each of the blades extend perpendicularly in respect to the propeller shaft, and thereafter the said blades extend in substantially a parallel direction in respect to the said shaft. It is still a further object to provide a support to the said propeller construction, that its cupped portion to be held in its designated position relative to that part of the blade extending perpendicularly from the propeller shaft. It is a further object to provide a support which will restrain the perpendicular portion of the blade and the cupped portion of the blade from vibration. It is still a further object to provide a support of sufficient width and of sufficient depth in relation to the perpendicular portion and the cupped portion, that it does not obstruct the flow of air across the propeller which it supports.

I have now discovered and invented a propeller which will hereinafter be clearly and fully disclosed and I am now able to avoid the disadvantages of the prior art and to accomplish the objects set forth.

While some of the more outstandin features, and advantages of this invention have been hereinbefore indicated, others will become apparent from the following disclosures, taken in conjunction with the accompanying drawing, in which:

Fig. 1 is a front view of a two blade assembly of the propeller.

Fig. 2 is a left side view of the Fig. 1.

Fig. 3 is a top view of the propeller in Fig. 1.

Fig. 4 is a sectional view of the same taken along the lines 4-4 of the Fig. 1.

Fig. 5 is a sectional view taken along the lines 55 of the Fig. 1. I l

Fig. 6 is a sectional view taken along the lines 6-6 of the Fig. 1.

t propeller.

2*, N Fig. is a sectional view taken along the lines 1-4 of the Fig. 1. g g V Fig. 8 is a sectional view taken alongthe lines 8 -8, of the I showing a portion of the engine shaft, a sectional view of the propeller hub, a por tion of the opposite propeller blade, and the spinner. A

Referring now to the drawing, and especially to the Figs. 1, 2, and 8, the spinner is designated by the numeral 1. The blade 3 are held in the sockets 2' by inserting each of the shanks 3a into their resp ve shanks. The said sockets are integral with and extend therefrom the hub 2a. The said hub is sec iiiedjtd the engine shaft H by means of the threaded end 12' of the said shaft, and the threaded holding ring I3. The numeral 4 designates the trailing edge of the propeller and the numeral 5 designates the leading edge of the propeller. This is best shown in the Figs. 1 and 2.

It will be noted by reference to the Fig. 1, that the propeller blades are shown in their actual structure but shown also is the manner'in which I accomplish the improvements on a conventional The dotted lines in the Fig. 1 show the conventional extension of the blades of the propeller and this is designated by the numerals Ta, and 8a, in which the numeral la is the support, extending before the final forging, and the numeral 8a designates the cupped portion 8 before final forging.

After the propeller blade has been formed, as shown by the dotted lines in Fig. 1, the ends of the propeller blades are cupped into the form shown in the full lines. The support then reinforces the ends of the perpendiculars, and the bends of the propeller blades.

The numeral 9 refers to the top of the cupped portion 8, and the numeral I0 refers to the leading edge of the cupped portion 8.

In the construction of the propeller blades of my invention, I want to point out that substantial latitude is permitted in respect to the length of the portion of the conventional blades which extend perpendicularly in respect to the engine shaft, and I want further to point out that substantial latitude is permitted in respect to the extent of the length, and to the extent of the angle of the bend of the cupped portion of the blade. I may increase or I may decrease the angle of the cupped portion of the blade, or the length of the cupped portion; and I may increase or decrease the length of the portion of the blades which extend perpendicularly in respect to the shaft. I therefore do not restrict my invention 3. to any particular size, or to any exactly defined shape, since a great deal of variation of size or if shape is permitted without the loss of efliciency, and the freedom of the scope of a principle involved is the means of achieving the ultimate utility of the principle.

In the operation of the propeller of my invention, the propeller derives its rotary motion from the engine shaft in the conventional manner, and the motion is counterclockwise as in Fig. 1. The numerals 6, I, and 8 indicate the portions which comprise the cupped portion of each of the propeller blades. When the blades rotate, the cupped portions of the blades compress the air as the air is centrifugally forced outwardly. When the air is so compressed the density of the same is greatly increased. The increased density gives the' air solidity, and in this state the air is of increased utility to the propellers direction for air flow.

Having clearly set forth the construction, utility and advantages of my invention I wish particularly to state that it will be apparent that changes in the details of the construction and arrangement of the various members of the invention may be resorted to without departing from the spirit and scope of the invention, as hereinafter claimed.

Iclaim:

A propeller comprising a hub, a plurality of blades extending outwardly from said hub, each blade having a shank portion generally circular in section, an airfoil section contiguous to said shank portion having its chord axis disposed at an acute angle to the plane of rotation of the propeller, a three sided cupped portion disposed outwardly of said airfoil section and facing in the direction of rotation of the propeller, said cupped portion having an outer surface of greater extent in the direction of rotation than the maximum width of the airfoil section and a leading edge of substantially greater width than its trailing edge, said cupped portion extending transversely to the plane of rotation of the propeller and one side of the cupped portion being curved and merging at its end into the leading edges of the cupped portion and airfoil section of the blade respectively.

GUY L. DAKIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 33,077 Elliott Aug. 20, 1861 283,592 Folmer Aug. 21, 1883 933,013 Ball Aug. 31, 1909 1,117,103 Steinbach Nov. 10, 1914 1,512,273 Callahan Oct. 21, 1924 2,086,307 Stewart July 6, 1931 2,269,287 Roberts Jan. 6, 1942 2,359,466 Currie Oct. 3, 1944 FOREIGN PATENTS Number Country Date Great Britain Feb. 24, 1921 

